[PATCH 3/4] tools: ynl: call nested attribute free function for indexed arrays

[Zahari Doychev <zahari.doychev@linux.com>]

When freeing indexed arrays, the corresponding free function should
be called for each entry of the indexed array. For example, for
for 'struct tc_act_attrs' 'tc_act_attrs_free(...)' needs to be called
for each entry.

Previously, memory leaks were reported when enabling the ASAN
analyzer.

=================================================================
==874==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 24 byte(s) in 1 object(s) allocated from:
    #0 0x7f221fd20cb5 in malloc ./debug/gcc/gcc/libsanitizer/asan/asan_malloc_linux.cpp:67
    #1 0x55c98db048af in tc_act_attrs_set_options_vlan_parms ../generated/tc-user.h:2813
    #2 0x55c98db048af in main  ./linux/tools/net/ynl/samples/tc-filter-add.c:71

Direct leak of 24 byte(s) in 1 object(s) allocated from:
    #0 0x7f221fd20cb5 in malloc ./debug/gcc/gcc/libsanitizer/asan/asan_malloc_linux.cpp:67
    #1 0x55c98db04a93 in tc_act_attrs_set_options_vlan_parms ../generated/tc-user.h:2813
    #2 0x55c98db04a93 in main ./linux/tools/net/ynl/samples/tc-filter-add.c:74

Direct leak of 10 byte(s) in 2 object(s) allocated from:
    #0 0x7f221fd20cb5 in malloc ./debug/gcc/gcc/libsanitizer/asan/asan_malloc_linux.cpp:67
    #1 0x55c98db0527d in tc_act_attrs_set_kind ../generated/tc-user.h:1622

SUMMARY: AddressSanitizer: 58 byte(s) leaked in 4 allocation(s).

The following diff illustrates the changes introduced compared to the
previous version of the code.

 void tc_flower_attrs_free(struct tc_flower_attrs *obj)
 {
+	unsigned int i;
+
 	free(obj->indev);
+	for (i = 0; i < obj->_count.act; i++)
+		tc_act_attrs_free(&obj->act[i]);
 	free(obj->act);
 	free(obj->key_eth_dst);
 	free(obj->key_eth_dst_mask);

Signed-off-by: Zahari Doychev <zahari.doychev@linux.com>
---
 tools/net/ynl/pyynl/ynl_gen_c.py | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/tools/net/ynl/pyynl/ynl_gen_c.py b/tools/net/ynl/pyynl/ynl_gen_c.py
index 58086b101057..aadeb3abcad8 100755
--- a/tools/net/ynl/pyynl/ynl_gen_c.py
+++ b/tools/net/ynl/pyynl/ynl_gen_c.py
@@ -861,6 +861,18 @@ class TypeIndexedArray(Type):
         return [f"{member} = {self.c_name};",
                 f"{presence} = n_{self.c_name};"]
 
+    def free_needs_iter(self):
+        return self.sub_type == 'nest'
+
+    def _free_lines(self, ri, var, ref):
+        lines = []
+        if self.sub_type == 'nest':
+            lines += [
+                f"for (i = 0; i < {var}->{ref}_count.{self.c_name}; i++)",
+                f'{self.nested_render_name}_free(&{var}->{ref}{self.c_name}[i]);',
+            ]
+        lines += f"free({var}->{ref}{self.c_name});",
+        return lines
 
 class TypeNestTypeValue(Type):
     def _complex_member_type(self, ri):
-- 
2.51.0